198 km SE of Perryville, Alaska

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

How big was it?

This earthquake released about 1.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 130,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 5,600× the energy of this one
3. Magna, Utah 2020 M 5.7 4,000× the energy of this one
4. This earthquake M 3.3 about 1.3 tons of TNT
5. Around the size people start to feel M 3.0 this one released 2.8× more

Energy from the Gutenberg–Richter relation (log₁₀E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

Where

Epicentre 54.7303, -156.7929. Map © OpenStreetMap contributors.

Aftershocks so far

58 earthquakes have been recorded within 50 km since this one.

1. 2.7 207 km SE of Perryville, Alaska 14:49 UTC
2. 3.3 195 km SE of Perryville, Alaska 14:25 UTC
3. 3.3 224 km SE of Perryville, Alaska 09:06 UTC
4. 3.3 212 km SE of Perryville, Alaska 05:13 UTC
5. 2.5 165 km SE of Perryville, Alaska 10:48 UTC
6. 2.5 196 km SE of Perryville, Alaska 05:23 UTC
7. 3.4 201 km SE of Perryville, Alaska 05:52 UTC
8. 3.2 199 km SE of Perryville, Alaska 16:48 UTC
9. 4.5 201 km SE of Perryville, Alaska 14:33 UTC
10. 3.0 180 km SE of Perryville, Alaska 07:33 UTC
11. 2.4 175 km SE of Chignik, Alaska 23:24 UTC
12. 2.6 199 km SE of Perryville, Alaska 19:43 UTC
13. 2.7 186 km SE of Perryville, Alaska 06:24 UTC
14. 3.1 202 km SE of Perryville, Alaska 06:08 UTC
15. 3.3 214 km SE of Perryville, Alaska 06:20 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 12:24 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

For this area

The largest earthquake within 50 km in our catalogue was M 5.6 on 2021-09-16 — it released about 2,800 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

• The official USGS event page — the source of record for every value above
• Did you feel it? Report it to USGS — reports go to USGS, not to us
• ShakeMap for this event, when USGS has produced one

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.